Removable cooling unit for



May 11, 1948. F. M. JONES REMmmaLE COOLING UNIT FOR GOMPARTMENTSOriginal Filed July 3D, 1941 5 Sheets-Sheet l o: ma;

May 1l, 1948. F. M. JONES REMOVABLE COOLING UNIT FOR COMPARTMENTS`original Filed July 30, 1941 e sheets-sheet 2 ns.. w

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F. M. JONES May 11, 1948.

REMOVABLE COOLING UNIT FOR COMPARTMENTS 6 sheets-sheet 3 Original -FledJuly 30, 1941 64 Invenolfl ttor-n.29.

. May 11, 194.8. F. M. JONES REMOVABLE COOLING UNIT FOR COMPAR'MENTSOriginal Filed July 30, 1941 6 Sheets-Sheef 4 Fig-1o 2.6 ./zlo

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May 11, 194s. F M. JONES Re. 23,000

REMOVABLE COOLING UNIT FOR COMPARTMENTS Original Filed July 30, 19.41 6Sheets-Sheet 5 Fig# 11 0 LY 1 M1 wf"- l x00;

T 'Il l May l1, 1948. F. M. JONES REMOVABLE COOLING UNIT FORCOMPARTMENTS Original FiledJuly 50, 1941 6 Sheets-Sheet 6 ZIO /iss 7 di,1 nn n o F IM L. m FMH, 8

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Reissues! May ll, 1948 nEMovABLE coouNG nNrr son ooMrAarMEN'rs FrederickM. Jones, Minneapolis, Minn., assignor to The U. S. Thermo Control Co.,Minneapolis, Minn., a corporation of Minnesota.

Original No. 2,336,735, dated December 14, 1943,

Serial No. 404,596,July 30, 1941. ApplicationV for reissue January 6,1947, Serial No. 720,464

My invention relates to a removable cooling unit; for compartments oftrucks, railroad cars and the like employed in transporting perishablesand toa method of cooling such compartments, and hasffor its object toprovide a simple and compact self-contained cooling unit positioned atthe top and at the front end of said compartment.

Perishables such as meatsvegetables, fruits and the like are transportedin what are known asv refrigerator cars by rail and, to a greatlyincreasing degree at the present time, in trucks and truck trailers.This transportation, taking place as it does over long routes which inthe summer time are at high temperatures throughout and even in thewinter time may be in part at high temperatures and in part at freezingtemperatures, requires artiilcial cooling or heat,- ing in order topreserve said perishables in suitable condition for use as food.

In the case of refrigerator railroad cars, heavy cooling means such aslarge ice compartments or large and heavy -refrigerating plants can bepractically employed. This is not true of trucks and trailers, where thenecessary limitations of their use call for cooling means of relativelylow weight and so positioned as to take up little as possible of thespace within the transporting compartment. t

It is a principal object of my invention, therei fore, to provide aAcooling unit small in size and weight, and positioned, together withthe airconducting passages, so as to occupy substantially none of thestorage space within the vehicle compartment.

A, It is a further object of my invention to provide a unit which shallbe mounted in the front wall of the compartment partly outside andpartly inside and having its top adjacent the top wall of thecompartment.

It is a further and particular object of my .in-

vention to provide a cooling unit embodying ay single unitary casingwherein is mounted allof the instrumentalities, including the powerunit, ior producing necessary movements of air and means for cooling orotherwise conditioning said air and means for controlling and-operatingthe several instrumentalities.

It is a further object of my invention to provide a unit embodied insuch a casing wherein the heating parts of the unit or the parts oi' theunit which normally give oil heat are located outside oi.' thecompartment to be cooled and the cooling part of the unit or the partwhich may deliver cooled air is located inside of the compartment.

Itis a further object of my invention to provide 4 Claims. (Cl. 6ft-117)operated by an expansion thermostat for causing said controlling meansto efi'ect control of operation of the gas enginein response to changesof temperature of the air about said thermostat.

The full objects and advantages oi my invention will appear inconnection with the detailed description which will now be given, andthe novel features by which the above noted advantageous results areobtained will be particularly pointed out in the claims.

In the drawings illustrating an application of my invention in one form:

Fig. 1 is a side sectional elevation view through the cooling unit asthe same is applied to the upper part of a food storage compartment suchas that of a truck.

Fig. 2 is a plan view with some parts in section and with the foodcompartment top removed to show that part of my cooling mechanismioundon the inside of the food compartment.

Fig. 3 is a perspective detail view showing the vforms of openingemployed for leading air out of the main air trunk. I

Fig. 4 is an end elevation view taken on line 4--4 of Fig. 2.

Fig. 5 is a top plan view of the entire unit as positioned in a foodcompartment with the top wall of said compartment removed.

Fig. 6 is a side elevation view of the entire unit as it appears whennot associated with the front wall of the food compartment.

Fig. '1 is a sectional elevation view through one wall of the unit takenon line 1--1 of Fig. l.

Fig. 8 is a fragmentary sectional view taken on line V8--8 of Fig. 7.

Fig. 9 is a transverse sectional view taken on line 9--9 of Fig. 1 andviewed in the direction of the arrows.

Fig. 10 isa transverse sectional view taken on line itl-i0 of Fig. 1.

Fig. 1l is a sectional transverse view taken on line II-ll of Fig. 1. f

Fig. 12 is a sectional transverse view taken on line I2-I2 of Fig. 1. v

Fig. 13 is a diagrammatic plan view showing the relation of thedifferent operating parts to each other and to the chambers forming theunit.

Fig. 14 is a sectional elevationV view oi the thermostatic carburetorcontrol Vtaken on line Il-il `or truck trailer.

3 Fig. 16 is an enlarged fragmentary sectional view through a corner ofthe casing and carburetor control mechanism and fiuid expansion mem- Asillustrated, and referring first to Figs. 5

, and 6, I provide a unitary interconnected'casing tops to horizontaltubular supports 28 and 29`Vl and at their bottoms to lower horizontaltubular supports 30 and 3I, as shown Iin Fig. 10. As shown in Figs. 1and 9, the supports 28, 29, 38

the front part I9 and inside of the side walls 23 and 24.

There is thus enclosed a front chamber 32v which in addition to thegrill 22 in the top is provided with grills 33 in each side wall, Fig.6. A grill 34 extends across the greater part of the bottom of the frontpart I9 and openwork indicated by holes 35 is provided in a Arear wall35, Fig. 9, all of which gives very free' circulation of air throughoutall parts of front chamber 32. The end wall 36, as shown in Fig. l,extends substantially across the rear of chamber 32 and has on each sidethereof' insulation indicated at 31 and 38 of Fig. 1 excepting for abearing housing 39 the use of which will be later described and adepression 48 for receiving an extension of a shaft member also referredto later.

'l'here is thus formed an insulated wall 4 I, Figs. 1 and 5, whichseparates the chamber 32 from the part of the unit which passes throughthe front wall of the truck into the interior of the truck compartment.This part of the unit comprises a top wall 42, side walls 43 and 44, anda bottom wall 45, Vas best shown in Fig. 9, which walls are united attheir corner junctions to the horizontal tubular supports 28. 28, 38 andI9 to the rear part of the casing 28, as shown in "and/3| are spacedconsiderably below the top of ful] and dotted, lilies in Figs. 1 and 9.The Walls 42, 43', 44 and 45 enclose a rear chamber 48 provided with aninnerz end wall 41, Fig. 1, which abuts the insulation V31 and'wall 4Iand an outer end 'wall 48,- 1. This outer end wall has a large inletopening indicated at 49 in Figs. 4 and 11 and an air outlet opening 58rectangular in shape and extending across the top of wall 48.

From the above description it will appear that the unit casing enclosesa front chamber 32 and 'unitary casing is an essential and exceedinglyimportant feature ofmv invention as the same is combined or applied tothe food storage compartment oi' a transport vehicle, such as a truckFor, as will be pointed out in detail hereinafter, the larger frontchamber will be applied to the front wall of such a compartment so thatit isentirely outside of the compartment, its numerous grills andopenings lead. ing directly to atmosphere, and it will houseall theheat-producing and heat-withdrawing instruing for this chamber and thechamber itself and its contents, which'may tend to cool the air, arelocated entirely within the food storage compartment, but positioned atthe central top where practically no effective storage space is used.

The unit is applied yto the front wall of the storage compartment, sothat it may be readily removed, if that becomes at any time desirable,in the following manner. A rectangular opening 53 is formed in theinsulated front wall 54 of the compartment. This opening has appliedthereto a frame 55 which is formed with vertical side walls 56 and 51and top wall 58 and bottom wall 59, as shown in Fig. 9, and which wallsare adapted to engage the edge walls forming the opening 53 extendingthrough the front Wall of the truck. Laterally extended. side flanges 5Iand 52 and top and bottom flanges 68 and GI extend from the walls 56 and51, and 58 and 59 respectively and engage the outside of the front wall54 of the truck.

The usual construction of food transport vehicles is well shown inA Fig.5, wherein an outer shell 62 of suitable material such as metal and asimilar inner shell 63 are spaced apart, the space being filled withinsulation 64. After the opening 53 has been formed in the truck bodyvertical 4wooden frame members 65, 66 are positioned between the outerand inner shells 62 and 63, and may extend from the top toward thebottom downward as far as may be desired. Secured to these frame pieces65 vand 66 by meansof bolts 61 are angle irons 68 and 69.A The bolts 61also pass through bracket flanges 18 fast on the tubular members 29 and3i, as shown in detail in Figs. 'I4 and 8, and by this means the.

entire unit is held rigidly assembled in the front wall 54 of the foodstorage compartment and yet so assembled that by merely removing thebolts 61 the vunit may bewithdrawn therefrom. Brace rods 1I 12 and 13extend in arched relation across the rear wail of -the unit, as shown inFigs. l, 4 and 6 and hold the parts rigidly together.

.Having reference particularly to Figs. l, 10 and 13, within the irontchamber 32 and transversely in alinement are a gas engine 15, acarburetor 16 therefor and a compressor 11. A support for the engine isindicated at 18 of Fig. 10 as being secured by bolts 19 to bracketplates supported by tubular supporting members 25 and 38. Similarly asupport 88 for the compressor 11 is supported upon tubes 25 and 3|.

Fast on motor shaft 8I is a pulley 82 which drives a pulley 83yoperating the compressor shaft 84, Fig. 10, by means of a belt 85. Belt85 also passes over a pulley 86 on fan shaft 81. The fan shaft 81,y asclearly shown in Fig. 1, lhas its fori ward end extended through asupporting bearing 88 and carries a fan 89 located in front chamber labout the condenser coil.

Also the condenser 90, as clearly shown in Fig.

- 1, is at the front end of front chamber 32 prorJecteri forwardly oi4the truck at the upper part thereof. where the pressure of the air asthe truck moves along the highway will aid the ian I9 in drawing airthrough the condenser. This air also is free to circulate all about theengine 15 and the compressor 11 and leave in practically all directionsthrough the numerous openings 22, 33. 34 and 35 provided f-or thatpurpose. Because of` this freedom of air to move out of compartment 32directly into the `open air in all directions.l it will be apparentthat, when cooling of the compartment takes place, none of the heatreleased by the gas engine, the compressor and the condenser, willaffect the walls 54 of the food storage compartment 96 Within the truck,or tend to warm the food storage compartment therein.

The blower 92 within front compartment 46 has a housing formed in theback by the closure 41 and in front by a typical blower casing' 91 shownin outline in Fig. 12. The casing 91 is formed with a central opening 98and with an internal passageway 99 surrounding the casingA andthe blower92 which progressively expands'l in width, as shown in Fig. 12, to thedischarge outlet into a top passageway lili within a casing |02 leadingto the air outlet opening 50 from the inner casing portion of thecomplete cooling unit. A curved top wall |03, Fig. 1, aids in directingthe air moved by blower 92 to and through the passageway |0|.

The passageway |0i and the casing |02 have their top wall |06 inengagement with a lining member |01 between the top wall |06 and theinner wall IDS-of the top of the compartment.

This passageway |0| is extended'nto a. passageway |09 formed by arectangular casing I I0, Figs. 2 and 4, which extends along the centraltop of the food compartment 96 directly in contact with the liner |01.

As shown at Fig. 2, the end oi the duct passageway |09 approaches therear wall i|2 of the food storage compartment 96. The duct passageway|09 has formed in its side walls ||3 and ||4 a series of openings ||5and ||5. These openings are specifically of the form indicated in Fig.3, wherein a lip ||6 is pressed inwardly between the top wall of casingI |0 and the bottom wall ||1. There also are formed in the side walls||9 and ||9 of the top duct |0I, Fig. 1, similar openings |20, Fig, 2,and 2|, Fig. 1only the lips 22, Fig. 2, are pressed outwardlyandibackwardly. Y

The arrangement of the several ducts IIE, H and of ducts and |2| is suchas to cause a sheet of cooled air to iiow from the central duct ||1outwardly along the top of the food storage compartment and to moveagainst all of the four surrounding walls of the compartment, thencedownwardly along said wallsto the door of the compartment, as clearlyshown in Figs. 2 and 4, with the result that an envelope of cooled airis caused to be formed and to move along allinterior walls of the fo'odstorage compartment.

This is the outward action of the blower. The inward or suctionaction ofthe blower causes air to move through an evaporator heat exchanger |23for-med of a series of transverse pipes |24 connected by pipe coils orunions |23 at the sides,

as shown in Fig. 1. The opening 49 to the evaporator heat exchanger |23is wel! shown in Fig. 11. The suction of `blower 92 causes the air to`move through the opening 49 underneath the outlet duct passageways |0|and ||1 and thence through to the opening 93 into the blower casing andthrough the blower 92 and back into the ducts |0| and ||1.

As shown in Fig. 4, the result of this operation is to draw into theblower and through the opening |23 air toward the top of the surroundingwall-contacting envelope of cooled air. This. of course, -will always bethe warmest air in the food storage chamber 36; and vbecause all of thewalls within the food storage chamber are wiped by the moving envelopeof cooled air which constantly takes up any heat tending to enter thefood storage compartmentthroughthe walls, channeling of air currentsandpoclceting and-r resulting dead air spaces are entirely avoided.Perfectly uniiorm cooling of the entire food storage chamber and all ofits contents at a minimum of cost results.

The arrangement of piping for conveying the compressed fluid to theevaporator is shown in the diagram, Fig. 13. In normal refrigeratingoperation the compressed fluid leaves the compressor cylinders to amanifold |44 and from there goes through a pipe |43 past a three-wayvalve |42, and through a pipe |4| into the condenser 90. From thecondenser 90 the liquid fluid goes through pipe |40 to receiving tank|39. From receiving tank |39 a pipe |38 passes through the separatingwall 36 and to and through a dehydrator |31. From the dehydrator |31 theliquid fluid passes through a pipe |36 and an expansion l valve |35 andenters the manifold head |34, from held in contact with suction gasreturn pipe |26,

Figs. 1 and 13. Gas pressure from thermostat ,|45 goes through tube |46to expansion valve |35 and regulates the rate'of flow of fluid toandthrough the evaporator heat exchanger |23.

The above is a standard and usual circuit for carrying out therefrigerating cycle.

For effecting heating of the heat exchanger |23 for defrosting andtransferring heat to the compartment by the same air-moving means ascirculates that air from the compartment through the heat exchanger forwithdrawing heat, I have provided the following simple arrangement.

The valve |42 may be an ordinary three-way valve in a casing to whichopens a pipe |49, Fig. 13. This valve |42 is provided with stem M1 andhand-piece |49 extending below the bottom wall of the front part of thecasing I9 to a position where it-can be conveniently operated by thetruck driver, as shown in Fig. l. This handpiece is employed for thepurpose of shifting the three-way valve to either of two positions. For

the retrigerating cycle it will close communicacondenser 95. In itssecond position it will open communication to pipe |49 through which thehot gas from the compressor will go through manifold |55 to the coils ofthe evaporator heat exchanger, irom which the hot gas is returned tomanifold |21, Fig. l. and goes through pipe I2 and manifold 11' back tothe compressor. v 1

Assho'wn in Fig. 13, this is the shortest direct route, and by-passesthe parts connected with pipe |45, although still connected withcondenser 95, passing the hot gas through the evaporator heat exchanger|23 where its heat maydo useiul work either in melting the frost on thecoils to eect deirosting, or in being transferred by the air circulatingmeans to the compartment to warm the same.

In the 'operation above described for vthe normal cooling cycle theevaporator is a cooling heat exchanger and the condenser a heatexchanger for giving ofi heat and dissipating it to Vatmosphere. Thatis, the air drawn through the evaporator heat exchanger by the blowerback of it is cooled air and coolsthe compartment. In the reverseoperation the air travelling as above described, drawn through theevaporator heat exchanger by the blower 92, will be heated air, which,if driven into the compartment for any considerable time, of course,would result in heatinar it.

When the direction of now is at last described Vi'r, may after theevaporator has been used for is to permit evaporation to maintain ahumid* atmosphere within the food storage compartment 95. As shown inFig. l1, a series of lopenings |55 in rear casing wall 45 leads to thespace |55 above the rear part oi pan |I. 4In practice masses ofcapillary material. such' as mineral wool, indicated at |51 of Fig. 12v,Will b Dui; in pan |5| both to increase the evaporating lsurface in thepa-n and to hold the water'therein against any substantial .movement dueto the operation of the truck. By these means the return air from vthefood Storage compartment will take up moisture from the large exposedsurface in pan |5| with the result that the interior of the food storagecompartment will have an atmosphere substantially moisture-saturated,which is of great value in transporting certain types of food stuns,such as meats, vegetables, fruits and the like.-

From gas tank 93 gasoline is fed to carburetor 15 in a customary manner.The carburetor, however, is adaptedto be held in one or the other of twopositions -for developing two speeds of the engine, an idling speed,which eile'cts practically no compressing action when cooling is notrequired, and a high speed for compressing and cooling. The means foreilecting this operation are shown in detail in Figs. l, 13, 14, 15 and16. These means are as follows:

A iluid expansion thermostat |55, Figs. 1 and 4, is connected by a tube|59 with a sealed chamber |'within a casing |5| depending from a secondcasing |52. Within the chamber |55, and

forming with'y said chamber a duid pressure responsive member, is ashell |53 formed oi a scries of convolutions. as indicated at |54 ofFig. 15. The space |55 within the member |53 is open at its top. asindicated at |55, Fig. 15, and further opens at |51, Fig. 14, throughthe casing |52 and into a chamber |55 within said casing.

In this casing |52 is pivotally mounted at |55 a frame |15 which carriesan upstanding arm |1| having on its end an armature |12 facing s, magnet|13. Extending horizontally is a second arm |14 which is guided by a pin|15 extending through a slot in its end. And extending through a slot|15 in the rear wall of casing |52 and `e'c'ured .to l-frame piece |15is a long leverarm v link |15 formed in part as-a spring |15 with theend of a lever |35, as clearly shown in Figs. 1 and 14. Arm |55 in turnis connected with a pivoted piece |52, as shown in Fig. l. Ihe pivotedpiece |52 is mounted at|53 upon the casing of motor 15, as clearly shownin Fig. 10. Fast on the inner end oi' piece |52 is a lever |54 which isconnected by means oi' a link |55 with the throttle lever indicated indotted lines at |55 on Fig. 1.

Mounted upon the base |5101! shell |53 is a plunger |55, Fig. 14, whichhas a pointed head |89 engaging the interior of a hemisphericalshapedmember |55 on horizontal lever arm |14. Over member |95 rests acorresponding depression in a cap |9|. Seated in this cap is acompression spring |92. the other end of which engages a cap |93 similarto cap |9I. 'I'he cap |33 ycarries a pointer |94 the end |94' or whichis adapted to move along a `plate |99 in a slo't 255,

Fig. 15. A thumb screw |91 has its shank |35 threaded into cap |93 by.means of which the degree of pressure exercised by the spring |32 may bevaried as desired. A rack mechanism |95 holds the screw .shank ,|95 inany adjusted position. The pointer end |34.' indicates thetemperature atwhich the control .will operate.

The cover 25| is removably held in position by positions of less orgreater distancel from magnet |13, whereby'the force of the magnet uponarmature |12 may be correspondingly varied.-

From the above description the operation of the construction may beunderstood as follows:

The carburetor is fed inv a well-known way by a tube 2|5 extending fromthe gas tank 53 to the oat chamber 2| l, Under normal conditions whenthe air conditioning mechanism is iirst set in operation the interior ofthe food compartment will be relatively warm. so that the iluid pressureresponsive .member |53 'will be contracted -to bring armature |12 withinthe operative force of magnet |13. This results in putting thecarburetor throttlein its position to operate the engine at desiredcompressing speed,

and takes place when the temperature within thev food storage chamber isabove the desired minimum.

As the temperature falls the gas in expansion thermostat |55 willcontract. and gas pressure4 The arm |11 is connected at its end througha to rock the frame on the pivot |69 and correspondingly rock arm |11,tending to close the throttle. As the closing of the throttle continuesthe speed of the gas engine will progressively decrease, having less andless compressing and cooling effect as the temperature within the foodstorage chamber 96 progressively falls. And when this temperaturereaches the desired minimum the spring |92 will have rocked frame |10and lever |11 and have operated the throttle to a point at orsubstantially at the limit of predetemxined possible movement of arm |14alone guide pin y |15, putting the motor into merely idling speed.

-partment the fluid in expansion thermostat |58 will expand and putincreased pressure in chamber |60, which will result in contracting orcompressing theud pressure responsive member |63 to cause it to moveframe |10 and connected levers |1| and |11, first to bringthe armature|12 nearer to the magnet |13 and then, if the temperature rise has beensufficient, to bring the armature to a point` where the pull of themagnet snaps the arm |1| against the end of adjusting screw 203. Thisagain will move the throttle to eiiect full speed of the motor.

It will be noted that the fluid pressure responsive member |58 islocated directly in front and toward the bottom of the opening 49leading from food-storage chamber 96 into the inner chamber 46 of thecasing and toward the bottom thereof thus being directly within thestream of return air goingto the evaporator cooling coils. Thetemperature control of operation of the motor is therefore based upontemperature of return air, which is substantially the warmest air withinthe food storage compartment. This in- 10 for causing cooling andcirculating of the cooled air therein.

Fourth, my invention provides means for distributing the cold air withinthe compartment wherein an envelope of said cooled air is caused to movealong all walls of the food storage chamber and the return of air to theunit is taken from within and toward the top cf this surroundingenvelope, thus at all times withdrawing the -warmest air from within thecompartment and effectively preventing any pocketing, dead air spaces,or regions of insuilicient cooling.

Fifth, a highly important and novel control of the motor is effected bymeans of an'expansion thermostat exposed to the return current o! airwhereby the carburetor is actuated to effect operation of the motor at alow or idling speed at which the fans or blowers will be suiiicientlyoperated to maintain movement of air in and from both chambers yof thecooling unit at lreduced rates of movement, and whereby the motor isoperated at a higher speed producing rapid movement of air in and fromthe unit chambers and thus effecting suitably rapid cooling where thatis called for.

sures not only a uniform operation of temperao ture shifts but also thatthe temperature shifts are based upon the warmest air within the foodstorage compartment and hence cannot leave unduly warm portions of airWithin the food storage compartment at any place or any time during theoperation of the device.

The advantagesy of my invention have been other chamber contains theevaporator heat exchanger, that is, the means for withdrawing heat fromthe compartment, In both chambers there are independent air movingmeans, that in the front chamber for forcing the withdrawn heat out ofthe system and that in the rear chamber for drawing the air through theevaporator heat exchanger and forcing the cooled air into and throughthe food storage chamber.

Third, the casing is mounted in the front wall of the food storagecompartment, such as is found in a truck or trailer at the top thereof,with the heat-releasing chamber outside where its numerous openingspermit quick discharge of all released heat to atmosphere, and with itscooling chamber entirely inside the food compartment Sixth, simple handoperative means is provided for changing flow of hot gas from thecompressor to and through the heat-exchanger by means of a shortenedcircuit for the main stream of gas, which still is connected with thecondenser. This shortened circuit otherwise bypasses the receiving tank,expansion valve and `'dehydraton and goes directly to and through theheat-exchanger and back to the compressor. What was the evaporator heatexchanger thus becomes 'a heating heat exchanger which can heat the airgoing through it to warm the compartment, or can merely melt ice on theheat exchanger for defrosting, the water from such defrosting going to apan preferably containing rock wool or other material so the air drawnover it by the blower-will take up the water and keep a high degree ofhumidity in all the air in the compartment.

A nnal and vvery material advantage of my invention resides in the factthat it is both relatively cheap to constructand install, is operatedeconomically and maintains itself in operation with a minimum ofadjustment and repair. l

1. In combination with a food storage compartment such as thecompartment of a transport vehicle having walls lexposed to outsideatmosphere, including a front wall having an opening therethrough,facooling unit comprising a single unitary casing the walls of which formtwo chambers, an evaporator heat exchanger secured to the casing in onechamber, lair moving means in said one chamber, a compressor andair-moving means and a gas engine for operating the compressor and bothair-moving means secured to the casing in the other chamber, the casingof the evaporator-containing chamber and said opening being relativelyof a shape and size such that said casing part may t inside and beprojected through the opening to. be within the compartment and theother chamber be outside the compartment and its walls exposed tooutside air, means in the casing vsupporting the iirst mentioned airmoving means and forming the dividing partition of said chambers forinsulating them one from the other, and means for se- 1l and all partsof the cooling unit may be readily removed therefrom as an entirety.

2. In combination with a food storage corri-- partment such as thecompartment of a transport vehiclelxavingwalls exposed to outsideatmosphere including a front wall having an opening therethrough, acooling unit comprising a single unitary casing the walls of which formtwo chambers, an evaporator heat exchanger secured to the casing in onechamber, air moving means in said one chamber, a compressor andair-moving means secured to the casingin the other chamber, a gas enginesecured? to the casing in said last-named chamber i'or operating the compresser and both air-moving means, the casing of theevaporator-containing chamber and said opening being relatively of ashape and size such that said casing part may lit inside and beproiecte'd through the opening to be within the compartment andthe otherchamber be outside the compartment and exposed to outside air, meanssupporting the rst mentioned air moving s'aid chambers for insulatingthem one from the other. means ior securing said casing, and partscarried'thereby on said iront wall so that the casing as an entirety maybe readily Vremoved therefrom, and means on the casingv portion withinthe compartment controlled by the temperature therein for controllingoperation vof the gas engine according to the temperature change demandamade ,upon the instrumentalities operated by the gas engine.

chamber 'having said evaporator therein 'and' 12 to be projected throughsaid opening so that said smaller chamber may be within the compartmentand the larger chamber outside the com partment and its walls exposed tooutside. air,

. means in the casing supporting the rst mentioned air moving means andforming the dividing'partition 0fV said chambers for insulating them oneVfrom theother, and means for securing said casing and parts carriedthereby on said iront wall so that the casing 'as an entirety and allparts of the cooling unit may be readily removed therefrom as anentirety.

4. Means for air-conditioning a closed compartment such as thecompartment of a transport vehicle, said means comprising a casing,refrigerating apparatus therein including an-evaporator, part of saidcasing including an encased having an air inlet opening and an airoutlet opening, means for causing a current of air to be conditioned tomove through said inlet. across said evaporator and discharging it`through said 'means and forming the dividing partition oi 3. Incombination with' a' food storage com- `V partment such asthevcompartment of a transport vehicle having walls exposedto'outsideatmosphere, including a i'ront wall having an openingtherethrough, a cooling unitvcomprising a single unitary -casing thewalls of which form two chambers. one oi' said chambers being larger inemes-sectional area than the other with part of its walls at the pointof junction with the walls o! the smaller chamber extending voutwardlytherefrom, aneevaporator heat exchanger secured to the casing inthesmaller chamber, air moving means in said smaller chamber, a compressorand air-moving means and a gasenglne for operating the compressorand-both air-moving means secured to the casing in the larger chamber,the construction of the casing adapting the part thereof enclosing thesmaller chamber outlet, a Sas engine mounted in the casing for operatingsaid refrigerating apparatus and said air moving means, an expansionthermostat p0- sitioned to be traversed by said current at the air inletopening, means for controlling operation of said gas engine. and meanscaused to b'e operated by said expansion thermostat for causing saidcontrolling means to effect control of operation of the gas engine inresponse to changes of temperature of said current-'of air.

'FREDERICK M. JONES.

REFERENCES orren- The following referencesare of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,943,965 Hulse v Jan.=16, 19342,056,353 Heinz Oct. 6, 1936 2,162,152 Wulle v June 13, 1939 2,180,915Stebbinst@ N0v.'21, 1939 2,206,631 Clark July 2, 1940 2,229,220 ParksJan. 21,r 1941 2,231,069 VHarris Feb. 11, 1941 2,257,221 Bell Sept. 20,1941 2,263,476 Sunday Nov. 18, 1941 2,266,187

